Method and apparatus for separating particles in a fluid dispersion



March 15, 1960 G DEAVER 2,928,591

METHOD AND APPARATUS: FOR SEPARATING PARTICLES Filed Dec. 27, 1956 IN A FLUID DISPERSION 2 Sheets-Sheet l INVENTOR. 650265 L. 0541/66 March 5, 1960 G. L. DEAVER 2,928,591

METHOD AND APPARATUS FOR SEPARATING PARTICLES IN A FLUID DISPERSION 2 Sheets-Sheet 2 Filed Dec. 27, 1956 INVENTOR. GEOEGE L. 0541 62 ///S 14 TTOEA/E'YS United States Patent METHOD AND APPARATUS FOR SEPARATING PARTICLES IN A FLUID DISPERSION George Lee Deaver, Columbus, Ohio Application December-27, 1956, Serial No. 630,857

22 Claims. (Cl. 233-2) This invention relates to a method and apparatus for separating particles in a fluid dispersion into groups according to their specific gravities and, more particularly, for separating the corpuscular particles in whole blood.

In recent years much effort has been directed toward developing means for separating various particles found in whole blood. Even .so, the methods for doing this which are presently commercially available are time consuming and, for the most part, capable of handling only small quantities of blood. An object of this invention is to provide a method for rapidly separating particles dispersed in a fluid medium, the particles separating according to their specific gravities.

Another object of this invention is to provide the apparatus for carrying out the aforesaid object.

Another object of this invention is to provide a centrifuge apparatus for separating whole blood into its various components.

Still another object is to provide an improved centrifuge apparatus for removing particulate-or corpuscular matter from a fluid dispersion. I

Another object of this invention is to provide a particle separating device wherein capillary tubes increase the rapidity of separation.

Another object of this invention is to provide a particle separating device wherein a column of fluids of varying specific gravity is employed to separate particles.

A further object of this invention is to provide a novel stopcock including a capillary filter for use in particle separation.

Still another object of this invention is to provide a novel stopcock valve having flush ports extending therethrough for clearing the capillary filter therein.

Other objects and advantages reside in the construction of parts, the combination thereof and the mode of operation, as will become more apparent'from the following description.

The efforts leading to the present invention have been confined primarily to a search for means for separating blood into its various components. However, the principles developed as a result of this research are applicable as well to other problems wherein it is desired to separate particles according to their specific gravities.

In order to better understand the present invention, the mathematical principles concerning the rate of separation of solid particles in fluid dispersions are reviewed. To a first approximation, the rate of fall of a' macroscopic solid particle in a fluid medium is given by the relationship, R=(d,d )Vg; where R is the rate of fall; d, is the specific gravity of the solid particles in the fluid dispersion; d: is the density of the fluid medium (gas or liquid); V is the volume of the particle; and g is the gravitational accleration. In whole blood, for example, the volume (V) of the various particles dispersed in the plasma is so small that, with the accompanying effects of Brownian motion and perhaps protective colloid action provided by the plasma, the rate of settling (R) is small. Hence, the red and white corpuscles and the' platelets ICC 2 dispersed in the blood plasma will only slowly settleout of the plasma. 7 1 r Frequently, a centrifuge apparatus is employed to separate the corpuscular matter from the blood plasma. The centrifuge is, of course, a means for artificially in: creasing the gravitational acceleration (g) to hereby in crease the rate of setting (R).

It is apparent from the equation stated above that if the specific gravity of the dispersing fluid (d,) is equal to the specific gravity of the dispersed'particles (d the term (d,d;)=zero and hence R=0 and no settlingcan take place, regardless of the volume of the particles '(V) and regardless of the acceleration (g)'applied. This condition is used in the present invention as a means for separating particles into groups of varying density; For example, if the particles in whole blood were dispersed in a cylinder containing an isotonic liquid, whereinthe specific gravity of the liquid was graduated from top to bottom of the cylinder, the particles would settle within the cylinder at various levels according to the specific gravity ofeach particle. From a practical view point,

although such a condition may be realized, the rate of settling with this technique is too small for effectively fractionating large quantities of whole blood. Applicant has designed a centrifuge apparatus wherein fluids of different specific gravities may be arranged in a column and yet maintained apart from one another so as to provide a column of fluids of varying specific gravity. A capillary filter provides the means wherebyparticles of varying specific gravities may be rapidly separated into groups. j r I In the drawings, i Figure l is a perspective view of a centrifuge apparatus for use in separating the particles in whole blood.

Figure 2 is an enlarged perspective view'of a modified centrifuge column.

Figure 3 is an enlarged perspective view of a second modification. Figure 4 is a plan view of a stopcock filter valve carrying a capillary filter used in this apparatus.

Figure 5 is an enlarged sectional view, taken along line 55 of Figure 1. V

Figure 6 is a sectional view, taken along the line 6-56 of Figure 3.

Figure 7 is a sectional view, taken substantiallyalong the line 7-7 of Figure 2. V 1 Figure 8 is a sectional view, taken substantially along the line 88 ofFigure 6. V

Figure 9 is a sectional view of a modification of the stopcock filter valve shown in Figure 4. V

Figure 10 is a sectional view of another modification of the stopcock filter valve shown in Figure 4;

Referring to the drawings in greater detail, a flask 10,

the

shown in Figure 1, serves as areservoir for whole-blood in the centrifuge apparatus. Ports 12 protrude from this flask it) to supply blood to centrifuge columns 13. The columns 13 comprise successively a first ch mber- 14, bounded by stopcocks 16 and 18, a second chamber 20, bounded by the stopcock 18 at one end and by a capillary filter 22 at the other end, and a third chamber 24,fl e nclosed by the flask 26. Disposed within valves 27 and 29 of the stopcocks '16 and 18 are capillary filters 28 and 28a respectively, which are formed from aplurality rate ted Mar. 15, 1960 large tube. o. Provide. holes and. drawingthe tube to.

reduce the diameter of the holes.

The column 13 formed by the first, second and third chambers may be broken. at any desired p int bu ground glass joints, such as that shown at 32 and 34', in;

Figured. Theselection of points at which ground glass joints. are. to. be: placed is' a matter of choice, depending; upon; the needs; for disassembling and cleaning the cen trifugez apparatus. In the device of Figure 1;, the centrifuge column 13 is integral with. the, flask '103S'fa1';

theground glass. joint, 32, 34, withv the capillary filter 22 being entirelyfremovable for cleaningv purposes. By]- providing ground. glass. joints on either side of-eachrstop cock-,it would. bepossible to interchange. the variousfparts; ofithacolumm individual: capillary filters and for withdrawinglliquidsitem the variqusl chambers by placing capillary ports- 36.. an various points along the column. The location. of the;

variouscapillary ports is again a matter of;choice',-,de= pending'uponthe; particular needs for the apparatus.

' The secontt chamber'201in the column 13 is actuallyxthe anaemia ithereingwhichhas a higher specific gravity than that of the platelets. The plasma, unable to travel through the filter 28, remains in the flaslc10.

, platelets from. the: plasma.

The. column 13.is.emptied. after the centrifuge operation'i'n'the following'manner; first,pthe'stopcocks 16 and Erovision; is made. in the. apparatus, for cleaningthe allelzrelationship "tozthescolumn-fii'and: air'is i again forced through-the capillary: port. 36b1,, thefluid in: the chambert hollowtof'the ground glass joint 32;"3'4. A'capillaryport;

r 30% draining through. the capillarystem 38;. The flask 26 is. provided forthischamberby placing a. capillary stern 381cm the outer joint member 34 and by; placing a hole 39in theinnenjoint member32 for registration with the capillary stem. The particular port" 36a may. be. closedaatcany. time, merely by rotating the portions of the ground; glass joint32, 34 relative to one another, to move thehole 39 out of registry with thestem 38.

The apparatus: is designed to be mounted upon a fientrifuge tahla the reservoir flask 10 being anchoreddirectly-oven the center 'of rotationofthe; table. Clamps 35, adapted to grasp the flask 10, are provided, for this purpose. 'The'several columns protruding fromthe cen tenfiaslc 10; may be anchored to the'table as desired.

In the operation of this device, the capillary ports 36 first closed: by suitable caps, *not shown, then a the fiasl; 10is filled with 'whole blood. The*whole blood contains plasma havingan averagetspecific gravity of about 1.024, red blood corpuscles having an averag'eespe gravity" of 1.095, white blood corpuscles having" an average specific gravity; of 1.059 and platelets having an average specifi'c gravity of 1.029. The diameter'ofithe particles in the blood ranges fromthree microns for the plateletsto an average/of fifteen microns for'thewhite thje' flask 26 is" charged'wi'th anisot'onic solution; having especific gr-avity-1.080.-

The apparatus is thenwhirled at high speed'upori' the centrifuge-;. table, accelerating the particles in the whole 18 are closed, .so;.that;.theicapillary filters therein are no longer in parallel relation to -thercolumn. This shuts off the chamber 14. Thechamber 14 is emptied by introducing air, or any other suitable fluid, into the cham her through: the: capillarypporr 36b; forcing the liquid containing; dispersed: platelets: through.- the capillary port 360.] The chamber 20 is inexti emptied byturning the:

sto'pcocle18g:Scrthat.thetcapillary:filtentherein is in paris: next. emptied by. separation; from the; column, at the ground: glassjoint:

- The relative sizesrofi the. chambers 14, .201 and 24 maybe varied in:v any desirable: manner. Thesizes shown in Figures 1iandiS;haveaevolved asta matter of; design con.- venience..

It will-be,:noted ini Figured that the'w allstof' the chamber 14 are'slanted asfin a cone. Ihis'shape/istprovided so that particles being accelerated through: the column willnot be obstructed outward travel by the Walls: of

the chamber 14, whichis 'larger in cross seetionz than the remainder of'the column-13$ Two modifications: of this device are 'shownin Figures 3 and 6 and Figures 2 and 7 ThemodifiedcolumnAog showndn Figures 3 is designed for separation. of red and whitecorpuscl'es from whole blood on" a smaller scale. The first chamber 42 of the -column corresponds in function to 'tlie flask 10 i'n' the preferred embodiment: Similarly, the second chamber 44 of the column 40 corresponds in function" to the second chamber 20 of'column- 1B: The third chamber in boththe preferred embodiment and thecolumn' 401is provided with a fiasle, suchias that shown at 26. a v

Aicapillaryport 47 isf provided in 'tliehollow of a stem 46 at the -top of the chamber'42i A first capillary filter 48 is provided in the stopcockfilter valve50 intermediate 'th e' chambers; 42 and" 441* second capillary filter 49 is fusedwitliin the column 40 below'fthe'second chamber blood out of? the flask 10 and through the columns 13 extending'froin" thefiask "10. The red blood corpuscles will travel'through the entire column 13 to the chamber which contains aisolution having a specific gravity equal approxirn'ately to that of the red-blood corpuscles. The white blood corpuscles will travel throughthe column to -the chamber'20 which contains a solution having 44: "It willb"e-"noted tliat=this arrangement provides a unitary column as opposedto the two piece column: 13

illustrated iniconnection:tvitlrtlie embodimentof'Figures -1 andS'i a 1 In..tl ie operation of" this; modification; whole blood is introducedintor the chamber42 throughtlie capillary 'port '47 which' facilitates filling, and servesto' keep foreign matter out of'the'chambe'r 42. Ah isotonic solution of specific (gravity L059 is" introduced into the chamber 44 andthe" filter 485, A capillary'port 52* passing through V 1.095?istintroducedinto the fiask,iwhich is attached tothe specific gravityequal approximately to that of the white.

corpuscles. They will not travel through the filter 22; since; the specific gravityofthe liquid in thilsgfilter 1.080 isaggeater than-that of the white blood cells-1.05 9. The platelets: will; travel only throughthe. first capillary filter in=the stopcock-16 ,tothe chamber 14-. They cantravel furthera through the column, since; they-are stopped at thesecondcapillary in the stopcock 1'8by the solution bottomof the' column*40l" Arr isotonic solution of specific gravityli080 'isiintroduced into the filter 49. The column '40 may; then be placed in: a" conventional centrifu iprovid'ewwitli'cups intoiwhich telst'tubes, or'the like, maybe inserted, the column" 401' being; insertedwith suitdapters;as"wouldfbeiaitesf'tube: As'the column rsjcentrifug edj, redicorpuscles travetfffoinitlie: chamber .;42to .the gbottomf flask and white. cells; travel... from-the Following the ccntrifuge'operation which takes about three minutes, the separated fractions are removed from the column 40 in the following manner. First, the liquid containing white corpuscles in chamber 44 and filter 48 is evacuated by suction through the capillary port 52 provided in the wall of the chamber '44. As this liquid is withdrawn, the plasma, containing platelets, which was initially in the chamber 42 flows under gravity into the filter 48 and the chamber 44, the operator interrupting the withdrawal of fluid when substantially all of the white corpuscles have been withdrawn. Subsequently, the plasma and platelets may be withdrawn through the same port 52. Finally, the red corpuscles are obtained from the bottom flask by opening the adjacent ground glass joint.

It isapparent that the column 40 of Figures Band 6 may be used also for merely separating the red and white corpuscles from the plasma and platelets by placing an isotonic solution of specific gravity 1.04, for example, throughout the column 40 below the chamber 42. During the centrifuge operation, both the red and white corpuscles will then be accelerated into the bottom flask.

The modified column 54 shown in Figures 2 and 7 is also designed for insertion into a standard centrifuge apparatus having cups into which a test tube or the like may be inserted. Inthis modification, whole blood is introduced into a reservoir chamber 56, through a capillary port 58. As in the preferred embodiment, a second chamber 60 is filled with an isotonic solution of specific gravity 1.029, a third chamber 70 is filled with an isotonic solution of specific gravity 1.059, and a flask, such as the flask 26, filled with an isotonic solution of specific gravity 1.095 is attached to the lower end of the column with a ground glass joint. Similarly, a capillary filter 62, disposed in a stopcock valve 64, is filled with an isotonic solution of specific gravity 1.029, a capillary filter 66, disposed in a stopcock valve 68, is filled with an isotonic solution of specific gravity 1.059, and a filter 72, disposed intermediate the chamber 70 and the flask 26, 'is filled" with an isotonic solution of specific gravity 1.080.

Platelets are centrifuged into the chamber '60, white corpuscles into the chamber 70 and red corpuscles into the flask at the bottom. Thus, the operation of the column shown in Figure 7. is identical to that shown in Figure 5. The fluids in the various chambers may be removed from the column of Figures 2 and 7 in a manner similar to that employed for the column in Figures 3 and 6, through a capillary port 74 extending into the second chamber 70. H

' Figure 4 shows a modified filter valve 76 which may be used in any of the centrifuge columns outlined in the above paragraphs. In the filter valve 76 a capillary filter 78 is provided along with capillary ports or channels 80. The ports 80 replace functionally the capillary ports 36'shown in the preferred embodiment of Figure 5. In the operation of the filter valve 76 for centrifuging, the capillary filter 78 is positioned parallel to the column in which it is employed. When it is desired to drain either chamber adjacent the filter valve 76, the valve is rotated so that the capillary ports 80 are connected into the adjacent column. Any suitable fluid may then be forced through the capillary port 80 .to flush the chambersconnected thereto. The filter valve '76, having capillary ports 80 integral therewith, has the advantage that the cost of the construction of a column such as that shown in Figure 5 is considerably reduced, it being unnecessary to provide the capillary ports 36. The ports 80 may also be interconnected to bypass the capillary filter 78. V

, A second modified filter valve 82, containing a capillary filter 84, is illustrated in Figure 9. It will be noted that the capillary filter 84 in this modified filter valve does not extend to the full diameter ofthe filter valve. Thisprovides for small pockets 86 at-each endof the capillary filter' 84.""-Connecting to these small pockets 86 are capillary ports 88, which may be used todrain the pockets and flush the capillary filter 84. The ports.

88 may also be used to recharge the capillary filter 84. with any desired fluid, the recharging operation being effected when the filter is in a non-parallel relationship with respect to the column, so as not to disturb any fluids in the column. As in the first modification of Figure 4, additional capillary ports may be provided in the filter valve 82 to provide for drainage of the chambers adjacent the stopcock carrying the valve 82. In the filter valve 82 the conventional handle has been replaced with cylindrical projections 90 extending from either side of the filter valve, which projections provide a rigid support for the capillary ports 88 and 80,. The filter valve 82 is designed to be rotated with a wrench (notshown) engaging a glass hex nut 92 fused to one side of the filter valve. 1

In Figure 10, a third modified filter valve 94 is illustrated. The filter valve 94 is formed from a hollow glass cylinder 96, the outer surface of which is ground to fit within a suitable stopcock. Extending diametrically across the cylinder 96 is a hollow tube 98, into which is fitted a capillary filter 100. Oppositely disposed hollow T-shaped tubes 102 are joined to the walls of the glass cylinder 96, the T-shaped tubes 102 replacing in function the capillary ports 80 of Figure 4.. The tubes 102 may be of capillary dimensions, or may be larger than capillary dimensions, each leg having therein a plurality of capillary tubes fused together to provide a capillary filter (not shown). As in the modification of Figure 9, additional tubes 104 may be joined at either or both ends of the tube 98 to provide for flushing of the capillary filter 100 therein. The filter valve 94 of Figure 10 has the advantage of light weight for use in centrifuge operations. A further advantage accrues from the ease with which the oppositely disposed tubes 102 may be interconnected to provide a by-pass channel for by-passing the filter 100. The filter valve 94'may be filled with any suitable light weight material, such as paraflin, so as to reduce the opportunity for breakage of the tubes 102 and 104. Additional support for the tubes 102 and 104 maybe obtained by sealing glass discs 106 to the ends of the valve 94. A glass hex nut 108 is provided for rotating the valve 94.

The specific gravities of the solutions placed'in the centrifuge colums herein described were chosen for the purposes of illustration only. It is apparent that many other combinations of specific gravities maybe used to obtain the desired results. For example, the table below, produced with reference to Figures 1 and 5, illustrates two combinations which will provide the desired separation of platelets, white corpuscles and red corpuscles from Whole blood.

- a ume desired; only one-capillary filter need be used,. manner;

being disposed between two chambers,. one containing;

thewhole blootl and one containing: an isotonic.liquid=,.-

which may be at either higher or" lower. specific gravity than that ofithe plasma; The only limitation. isthat-the' specific gravity of the isotonic solution be less than that;

ot the' plateletsi When sucli a columnris centrifuged;the."v

corpuscular matterinz the: whole blood: will? travelathrolugln the capillary" filter;, thu's: separating from the plasma.

In other applications, it: may: be: desired to: merely; oh

7 tain a particle density distribution. from a. dispersion: oft

intereeneeetedehmbezsaplaeingtiauhetehmim .tliquid" s i oiavar yingi specificgravity; covering; the range: within! which; separation. of rthe corpuscular matter: is to be; effected; the liquidskbeing; orientedwithin theacolumm in: order of: increasing specificgravities, the 'liq-uid 05 highest. specific gravity; being placed at: the. end. of the; column. opposite" the liquid. dispersion,- placing a filter: intermediate each pair of. adjacent chambers, the: filters .each; having at leastone: passage therethrough: which is I of capillary dimensions; and centrifuging. the column so: as to accelerate particles out: of the; whole bloodand;

through: the column toward the opposite end: ofthe column.-

particles in a gas orliquidamedium. In such an appli-i cation; aplurality o'f -chambers?interconnected=withcapillar-y filters may heprovidedi in' a: column;.the chambers:

being filled withgas on liquids 70f varying specific: gravi? ties; When the dispersion isg'placedabove the: column and centrifuged, particles: will orient. themselves.- the column according'fto their specific? gravitiesr: and. the? pa rticle distribution thereby obtained;

Ill this des cription, fr'equent referenceshasi bcenzmad'e to' theterms capillary-port and capillary; filter. The term- "capillary port is employed todesignate. either a port which is-of capillary' dimensions or a port into whichhas b'e'en fused plurality of capillary tubes. Capillary; port's;are.=employed inthe present invention to provide a nteanswherehy fluid new canlbe accurately controlled The term fcapillarw filter? refers. to: azfilterl formed; hp fusing together a plurality of.capillaryjtub'eszt This; at.- rangement is: termeda filter for the reason that in the present useythef capillaryr filter. functions to permiti the passage of particles therethrough; whileeimpeding .the' intermixture: of fluids placed? on. either side of' theifilter:

3t 1 he methodofi; separating. particles: in a liquid: dis? persion into groups of varying specific gravities, comprise 'ing the steps of placing the liquid dispersionat' one end" of ta column. having.- thereina plurality of interconnected. alignedchambers,,placing.in theIchamberstliquidsoftvarying specific g'ravities coveringthe range. within whichparr' ticlesseparatio'n istto he=efleeted the liquids being ,oriented withimthecolumn-in orderof increasing spccifictgravitiesa the; liquid. of; highestv specif c. gravity. being: placed at the.

7 endofithe column. opposite the; liquid. dispersion, said Iiquidsbeingchemically inert.withregardtothedispersed particles placing afilter intermediate each pair of..ad=' jacent. chambers, the filters. each .having'at least: one passage therethrough which is.of.capill ary dimensions,.andf

centrifuging.thecolumnso asto accelerate particles out- The explanationifcr 'the.behavion'of such atfilter .isrndt yet.

known; it having Been-observed; for example; that the" meref presence of 'capillary tub'es in anlordinarywcentrifugecell will! enhance the operation; of; this c'entrifuget- It of theliquid. dispersion througlrthe column toward the. oppositeend of. the column. b p

4.- Themethod of separating. particles ina liquidldis= persion into groups of varying. specific. gravities. comprise i'ngtth'e steps of placingthe. liquid dispersion at one. end ofa column. having. therein a plurality. of interconnected} aligned; chambers; placing: in. the. chambers liquids of varying .specific gravitiesscovering the .range within which separationof particles is I to. be; effected the liquids l being, oriented meme; oflincreasing specific. gravity,-.the,liqii idi of highest specific gravity, being; placed; at the, end of. the ,colurnnt opposite the. liquid dispersion, placing a filter;

intermediate each pain of adjacent. chambers, ,the' filters each havingat least one passageiof capillary dimensions extending .therethroughlandinterconnecting,the chambers adjacent=theretop and centrifuging. the column so as to.

he'en'adescribedgcit will '{be understood that-within :thepur View of this inventioni variousichanges may. be made in the form, detailsyproportion and-arrangement -ofiparts, the%-- combination": thereof-: and mode. of f operation, which generally stated consist-:- in. a: deviceicapableof carrying ontsth'et. objects a set forth; as a disclosed and defined: in the appended claims. a v V Having, thus. described my invention, 1' claim: l 1. The method of separating particles in a fluid disper sioninto gro'ups of difiering specific gravities, comprising the steps of; placing the fluid dispersion at one end of a column having therein a plurality of .aligned'chambers,

' placing in. the chambers fluids of varying specific gravities covering the range. within which, 'a particle separation is. to be eifectedythe fiuids beingoriented within the" dimensions, while impeding, the passage of fluids there! through, andment'rifugingthc columnso'asto accelerate the. particles. in: the fluid dispersion; toward. the opposite end of: the. column. g

. 2. The; method-.ofz: separating the corpuscular; mattetrv accelerate particles out of'tlie liquid dispersion-throughthe c'olim'uiv toward the opposite end of. the column.

5; The method of s'eparatingthe corpuscular matter of whole blood. into groups according. to thespecific gravi ties of'the corpuscular matter, comprising. the-steps of placingthe. whole blood containing platelets; white co'r' puscles, andredcorpuscles in'a' first chamber atone e'nd.

of acolumn having therein four interconnected aligned chambers; placing in the second of"said chambe'rs:an.iso'- tonicliquid having aspecific gravityi'comparable to that of the platelets,.said secondichambcr. being adjacent the.

'fii'st chamber, placing. in. the third ofl'said" chambers an isotonic liquidlhavinga specific.gravity eoinpa'rableyith in? wholei bloodtinto." groupss according;- to; specific 1 gravity cbmprising 'i the steps; oft placing; the.- whol ez: hlood. at; one;

that: of the. white. corpus'cle's, said; third chamber" being. adjacentsaid. second'cliamben. placing iii the fourth chamber an isoto'nic liquid having. a specific gravity. comparable-tov that of the red cor 'nu sclt'as,.{said' fourth" chamberr being adjacent saidttliirdch'amber. and. at the oppositeend of the column .from thewholblood,placing filter means intermediate eaclipair ofl adjacent chamhers} the filters.- each. having. passages. extending; therethrougli.

whichare of capillary dimensions, and centrifugingthe' columnso asto accelerate the corpuscular. matter. outo'f the: whole blood. and. through. the column. toward. theo'pposite end of the column.

, 6; llhe method of;- separating, the. corpuscular matter of whole': blood. into groupsza'ccordingltothe' specificigravit tiesg of. the corpuscular? matter; comprisingfi thesteps: of. placinglwh'ole bloodcontainingiplatelets; .whitezcnrnusclee and: red corpusclesj in a: first? chamber. at on of; as

m colunjnrha'ving .th r imroueint conneetedtalignedactia ay bers, placing in the second of said chambers an isotonic liquid having a specific gravity comparable to that of the platelets, said second chamber being adjacent the first chamber containing whole blood, placing in the third chamber an isotonic liquid having a specific gravity comparable with that of the white corpuscles, said third chamber being adjacent said second chamber, placing in the fourth chamber an isotonic liquid having a specific gravity comparable to that of the red corpuscles, said fourth chamber being adjacent said third chamber and at the opposite end of the column from the whole blood, placing filters intermediate each pair of adjacent chambers, the filters each having passages extending therethrough which are of capillary dimensions and centrifuging the column so as to accelerate particles out of the whole blood and through the column toward the opposite end thereof, the red corpuscles accumulating in said fourth chamber, the white corpuscles accumulating in said third chamber and the platelets accumulating in said second chamber.

7. A centrifuge apparatus for the separation of particles from a fluid dispersion, the particles being separated according to specific gravities, said apparatus comprising a reservoir flask for containing said fluid dispersion, the flask being adapted to rotate about a central axis thereof, at least one centrifuge column protruding therefrom, said column having therein a plurality of linearly aligned chambers, and a plurality of capillary filters disposed within said column, there being one capillary filter intermediate each pair of adjacent chambers, each capillary filter having at least one capillary tube extending therethrough,

8. A centrifuge apparatus for the separation of particles in a fluid dispersion into groups according to specific gravity, said apparatus comprising a reservoir flask for containing the fluid dispersion adapted to be rotated about a central axis thereof, at least one centrifuging column protruding therefrom, said column having therein a plurality of linearly aligned interconnected chambers, a plurality of filters disposed within said column, there being one said filter intermediate each pair of adjacent chambers, each filter having passages extending therethrough which are of capillary dimensions.

9. A centrifuge apparatus for the separation of particles in a liquid dispersion into groups according to specific gravity, said apparatus comprising a reservoir flask for containing said liquid dispersion adapted to be rotated about a central axis thereof, at least one centrifuge column protruding therefrom, said column having therein a plurality of linearly aligned interconnected chambers, a plurality of filters disposed within said column, said filters each having passages extending therethrough which are of capillary dimensions, there being o'ne said filter intermediate each pair of adjacent chambers, and port means having a substantially circular-cross section and having a first channel therein extending normal to and passing through the axis of rotation thereof, a capillary filter disposed within said first channel, said capillary filter having at least one capillary tube extending therethrough, said valve having a second channel therein connecting from one end of said first channel to one end of said valve whereby fluids may be introduced into or removed from the fluid stream regulated by said stopcock.

13. A filter valve according to claim 12 wherein said second channel is of capillary dimensions.

14. A filter valve according to claim 12 wherein a plurality of capillary tubes are inserted into said second channel to provide a capillary filter therein.

15. A rotatable filter valve for a stopcock, said valve having a substantially circular cross section and having a first channel therein extending normal to and passing through the axis of rotation thereof, a capillary filter disposed within said first channel, said capillary filter having at least one capillary tube extending therethrough,

said capillary filter having a length shorter than that of the first channel so as to provide pockets in said channel adjacent thev opposite ends of said filter, said valve having means therein for flushing the capillary filter.

16. A filter valve according to claim 15 wherein the means for flushing the capillary filter includes a second channel extending from one end of said valve to the pocket at one end of said capillary filter, and a third channel extending from one end of said valve to the for conveying liquids to and from each of the chambers.

10. A centrifuge apparatus for the separation of particles in a liquid dispersion into various groups according to specific gravity, said apparatus including a centrifuge column having a plurality of linearly aligned chambers therein, one of said chambers serving as a chamber for containing the liquid dispersion, and a plurality of capillary filters, there being at least one capillary filter intermediate each pair of adjacent chambers in said column, each said capillary filter having at least one capillary tube therein.

11. A centrifuge apparatus for the separation of particles from a liquid dispersion, said apparatus including a centrifuge column having a pair of linearly aligned chambers therein, one of said chambers providing a reservoir for said liquid dispersion, the other of said chambers providing a collection chamber for the particles separated from said dispersion, and a stopcock having a filter valve therein, a filter having passages of capillary dimensions disposed within said valve, said stopcock being disposed between the chambers of said column.

12. A rotatable filter valve for a stopcock, said valve pocket at the other end of said capillary filter.

17. A rotatable filter valve for a stopcock, said valve having a substantially circular cross section and having a first channel therein extending normal to and passing through the axis of rotation thereof, a capillary filter disposed within said first channel, said capillary filter having at least one capillary tube extending therethrough, said capillary filter having a length shorter than that of said first channel so as to provide pockets in said channel adjacent the opposite ends of said filter, said valve having channel means therein for flushing the capillary filter, said valve having an aperture located on the periphery thereof aligned with and intermediate the ends of said first channel, said valve having a second channel extending from one end thereof to said aperture whereby fluids may be introduced into or removed from a fluid stream regulated by the stopcock.

18. The method of separating the red and white corpuscles of whole blood, comprising the steps of placing the whole blood containing white corpuscles and red corpuscles in a first chamber of a column having therein three interconnected aligned chambers, placing in a second chamber of said column an isotonic liquid having a specific gravity comparable to that ofthe white blood corpuscles, said second chamber being adjacent the first chamber, placing in a third chamber of said column an isotonic liquid having a specific gravity comparable with that of the red corpuscles, said third chamber being adjacent said second chamber, placing a filter intermediate each pair of adjacent chambers, the filters each having passages therein which are of capillary dimensions, and centrifuging the column so as to accelerate the corpuscular matter out. of the whole blood and through the column toward the opposite end of the column.

19. The method of separating red and white corpuscles from whole blood, comprising the steps of placing whole blood containing white corpuscles and red corpuscles in a first chamber at one end of a column having therein two interconnected aligned chambers with a filter therebetween, said filter having passages therein which are of capillary dimensions placing in the second of said chambers an isotonic liquid having specific gravity comparable to that of the white blood corpuscles, and centrifuging the column so as to accelerate the red and white corpuscles out of the whole blood and through the filter means to the second chamber thereof.

20. Ar centrifuge apparatus. for the? separation oi paw.

rnedi ate the reservoir flask and the collection flask, saidfilter means having passages therein which are of 'capillary dimensions.- 1 a 21.- A. centrifuge apparatus for theseparation of. particles from. afluid dispersion, said apparatus comprising inf linear alignment a reservoir flask, acapillary filter, and;a collection flask, the capillary filter being disposed intermediate: the reservoir. flask and the collection'flasli, said capillary filter comprising. a plurality of,. capillary tubes extending, betweenthe collection flaskand the reservoir flask, p

22'. The method oftseparatingparticles in a fluid dis- 'persion into. groups of differing specific gravities comp'risingzthe steps. of placing the; fluid dispersion at one. end. of a column havingtherein a plurality: of aligned chambers,.placing fluids of varying. specificv gravitiesinto the various chambers: of the column, the. fluids. being oriented Withll'llthfi column in. order of. increasing specific gravity,..the fluid. of. highest specific gravity being. placed at the other end ofithe column, placingfilters intermediate each. pair. of adjacent chambers, thefilters each: having parallel passages extending therethroughwhich are of capillary dimensions, and accelerating the particles. in. the

fluidr dispersion toward the opposite endof. the column.

7 ReferntesGitedJn-tliefile of thispatent- STATES: PAH:

2231:573 Ainsworth e't'ali Y Ian; 13}

231,283; C'usliing' Aug. 17; 1880 4563242 Ebert July 21",. 1891; 591,394 Fahy Oct. 12,. 1897; $1 1,335 Gathmahn D'ec. 30; 1902; 766E364." Woolworth' May 17',-1J904 780;3'34" Freeman Jan. 17, 1905 7 1,332,639. Spaulding. Mar. 2,. 1920. 2,147,192; Knight Feb. 21, 1939 "2 ;1 5'0*,9 17 Foulke et' al. Mar; 21; 1939 2128139819; 'P'arfe'ntjer" May 5,1912 2,484,003 Si1nison" Oct; 4;. 1949 2,621,013. Mansfield .5 Dec. 9', 1932f 2.6781159 11152 May 11 1954 Tullis Mar; 19;. 1957-:

Tunis-er aT i: New Rr'incipleof'closed' System Centrif ligation, Science, vol. 124. r

Tullis': Separation and Purification of L'eokocytes'and Platelets, The Journal of Hematology, September 1952; pp) 891L896;

UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION 7 Patent Nos 2 928591 March 15 1960 George Lee Deaver It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below'o Column 2 line 6 for "hereby" read thereby column 7 lines 68 and 69 strike out "while impeding the passage of fluids therethroulgh "a Sighed and sealed this 30th day of August 1960.

FISEAL) Attest:

ROBERT c. WATSON "attesting; Officer Conn'nissioner of Patents 

